Released: May 01, 2003
Spring 2003 May Be Heaven for Dust Mites
MANHATTAN, Kan. Ė People get itchy just thinking about dust mites.
The human-skin-flake eaters are too small to see. But they live on such fabrics as carpet and rugs, upholstered furniture, drapes, stuffed toys, and bedding. In trade, they cause allergic reactions.
Fortunately, dust mites donít really like Kansas. Unless a building has high enough humidity to grow mold, dust mites arenít likely to build up large populations, said Ludek Zurek, entomologist with Kansas State University Research and Extension.
If they have a favorite time of year, however, itís probably spring Ė particularly the kind of spring Kansas is having in 2003.
Kansasí small dust mite populations tend mostly to die off in winterís dry furnace heat and then try to build up again when spring brings warmer outdoor temperatures and higher humidity levels, Zurek said. This spring has been mild enough that many people already have turned off their furnaces, but not turned on the air conditioner. Humidity often has been near 100 percent, even on days without rain.
Between the moist days and ongoing schedules for work and school, Kansans have been spending many hours indoors. And, dust mitesí favorite eating places are where people spend a lot of time. Beds and well-loved plush chairs are prime sites, the entomologist said.
But dust mites also can live in house dust Ė which seems to explode in spring as pets shed their winter coats and humans store away winterís wools and bring out the cottons. The mites become only one of the many ingredients in house dust that can cause allergenic reactions: pet dander, feathers, lint and fibers, mold and fungus spores, bacteria, food particles, insect parts.
"The dust in your house is rarely what makes you sneeze," Zurek said.
People sometimes spend time and money on attempting to reduce dust mite levels by having their home air ducts cleaned, he said. Forced air systems can and do blow around dust mite feces and the skin that the mites shed as they grow.
The proteins in that combination of feces and skin sheddings are what cause allergic reactions in humans. Depending on the person and exposure, reactions can range from itchy eyes to asthma attacks.
But dust mites themselves canít live in air ducts, Zurek said. To survive, these tiny relatives of spiders need organic food, such as dead skin flakes from people and pets, plus at least 70 percent humidity.
Both university and National Institutes of Health research has found that simple measures will keep Kansasí level of dust mites in check for all but the most sensitive persons, he said. Those measures include:
* Wash bedding weekly in hot water, preferably at least 130 F.
* Vacuum carpets, floors and upholstered furniture regularly and thoroughly; then discard the vacuum bag immediately. If you suspect you have a dust mite buildup, use a high efficiency particulate arresting (HEPA)-filtered bag or HEPA-equipped vacuum, and perhaps wear a paper dust mask while sweeping.
* Occasionally dry-steam clean carpets and, if you can, upholstered furniture.
* Encase mattresses, box springs and pillows in allergen-proof covers. In winter, take mattresses and such outdoors for a few hours to expose the mites to freezing temperatures.
Further actions Ė buying dehumidifiers, getting rid of carpets and drapes, switching to vinyl-covered furniture and the like Ė should be unnecessary for any Kansan who doesnít have severe allergy problems, Zurek said.
K-State Research and Extension is a short name for the Kansas State University Agricultural Experiment Station and Cooperative Extension Service, a program designed to generate and distribute useful knowledge for the well-being of Kansans. Supported by county, state, federal and private funds, the program has county Extension offices, experiment fields, area Extension offices and regional research centers statewide. Its headquarters is on the K-State campus, Manhattan.
Ludek Zurek is at 785-532-4731